1. Field of the Invention
The present invention relates to a photo- and pressure-sensitive recording paper and a pressure developing apparatus for developing the photo- and pressure-sensitive recording paper.
2. Description of the Prior Art
As recording paper to be used with a light imaging apparatus, there has been known recording paper coated with a layer of microcapsules each enclosing a substance which has hardness changeable by irradiation with light and which includes a dye precursor, for example, a photosetting substance or a photo-softening substance, and also coated with a developer. With the photo- and pressure-sensitive recording paper, a latent image is formed on the surface of the recording paper corresponding to the original and corresponding to the degrees of hardening or softening of the microcapsules, and then pressure is applied to the surface of the recording paper to destroy the microcapsules so that a reaction is caused between the dye precursor and the developer so as to make the latent image visible. In this process, undesirable coloring is apt to be occurred due to improper destruction of the microcapsules, and therefore great pressure is required in developing the recording paper.
Conventionally, photo- and pressure-sensitive recording paper has a support coated with a layer of microcapsules each enclosing a dye precursor composed of a substance having hardness changeable corresponding to a quantity of irradiation with light and coated also with a developer. Then, the microcapsules which have been variously changed in hardness corresponding to the varieties of quantity of light irradiation are destroyed to an extent corresponding to the variously changed hardness, so that changes in state of reaction between the microcapsules and the dye precursor caused corresponding to the extent of the destroy, and hence resulting changes in density of a developed picture, is utilized to perform development. This is a principle of development utilized for the conventional photo- and pressure-sensitive recording paper. In such conventional photo- and pressure-sensitive recording paper, microcapsules have been used only for the dye precursor and the developer has been directly applied on the support.
Therefore, if the microcapsules enclosing the dye precursor were destroyed for some reasons, for example, by accidental application of pressure, coloring was caused at portions where the microcapsules were destroyed. This tendency of the conventional photo- and pressure-sensitive recording paper makes it difficult to handle the paper. The conventional photo- and pressure-sensitive recording paper has a further disadvantage that it has to be processed by a large-sized pressure developing apparatus because high pressure is required for the destruction of the microcapsules.